CCL3 and COVID-19: Consistent with these results, the expression of pro-inflammatory or chemotactic cytokines in 3N39v2-Fc-treated lungs at 5 dpi showed decreased level of interleukin (IL)-6, interferon (IFN)-γ, IFN-λ, CXCL10, CCL3, CCL5, as well as IL-10 and TGF-β that are also associated with COVID-19 severity35, 36 (Fig. 5g, Supplementary Fig. 13).